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Mari Lundstrom - One of the best experts on this subject based on the ideXlab platform.
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process simulation based life cycle assessment of cyanide free refractory gold concentrate processing case study Cupric Chloride leaching
Minerals Engineering, 2020Co-Authors: Heini Elomaa, Jari Aromaa, Lotta Rintala, Mari LundstromAbstract:Abstract The development of cyanide-free gold leaching methods is becoming increasingly important due to the treatment of complex ores, where treatment by cyanidation is not economically viable. Cupric Chloride leaching provides an alternative leaching process to replace cyanidation. A detailed simulation of refractory gold concentrate processing by Cupric Chloride leaching is presented in this study. The simulation with mass and energy balances was built to be used as life cycle inventory data to evaluate the environmental impacts of the development stage Cupric Chloride process. Three cases, the Base Case (125 g/L Cl-), Mild Case (50 g/L Cl-), and Extremely Mild Case (20 g/L Cl-), were investigated in two flowsheet options. Loss of gold to wash waters was observed in the Flowsheet 1 cases, and therefore Flowsheet 2, with the recirculation of wash water to solvent extraction, was developed and investigated in order to achieve higher gold recovery. The gold extraction improved from around 85% to 99%. Chemical consumption (NaCl, NaBr, CuCl2) was greatly affected by the leaching conditions, higher concentrations consuming more initial chemicals. In milder conditions, efficient recycling of Chlorides could be obtained in the process, and no addition of NaCl was required. In the Extremely Mild Case, the Chloride concentration was close to sea water conditions (20 g/L), where sea water could be used to provide Chlorides for the process, and the effluent waters could be disposed of in the sea after purification. The global warming potential was estimated to be 12.5 t CO2-e/kg Au in Chloride leaching and was further decreased to 10.6 t CO2-e/kg Au in the mildest conditions (20 g/L Cl-). The milder Chloride leaching conditions (20 g/L Cl- and 50 g/L Cl-) were shown to decrease the acidification potential, eutrophication potential, and water depletion.
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Process simulation based life cycle assessment of cyanide-free refractory gold concentrate processing – Case study: Cupric Chloride leaching
Minerals Engineering, 2020Co-Authors: Heini Elomaa, Jari Aromaa, Lotta Rintala, Mari LundstromAbstract:Abstract The development of cyanide-free gold leaching methods is becoming increasingly important due to the treatment of complex ores, where treatment by cyanidation is not economically viable. Cupric Chloride leaching provides an alternative leaching process to replace cyanidation. A detailed simulation of refractory gold concentrate processing by Cupric Chloride leaching is presented in this study. The simulation with mass and energy balances was built to be used as life cycle inventory data to evaluate the environmental impacts of the development stage Cupric Chloride process. Three cases, the Base Case (125 g/L Cl-), Mild Case (50 g/L Cl-), and Extremely Mild Case (20 g/L Cl-), were investigated in two flowsheet options. Loss of gold to wash waters was observed in the Flowsheet 1 cases, and therefore Flowsheet 2, with the recirculation of wash water to solvent extraction, was developed and investigated in order to achieve higher gold recovery. The gold extraction improved from around 85% to 99%. Chemical consumption (NaCl, NaBr, CuCl2) was greatly affected by the leaching conditions, higher concentrations consuming more initial chemicals. In milder conditions, efficient recycling of Chlorides could be obtained in the process, and no addition of NaCl was required. In the Extremely Mild Case, the Chloride concentration was close to sea water conditions (20 g/L), where sea water could be used to provide Chlorides for the process, and the effluent waters could be disposed of in the sea after purification. The global warming potential was estimated to be 12.5 t CO2-e/kg Au in Chloride leaching and was further decreased to 10.6 t CO2-e/kg Au in the mildest conditions (20 g/L Cl-). The milder Chloride leaching conditions (20 g/L Cl- and 50 g/L Cl-) were shown to decrease the acidification potential, eutrophication potential, and water depletion.
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Effect of redox potential and OCP in ferric and Cupric Chloride leaching of gold
Hydrometallurgy, 2020Co-Authors: Sipi Seisko, Jari Aromaa, Mari LundstromAbstract:Abstract The research presented contributes to the global goal of responsible production by providing robust tools for the optimization of gold dissolution in cyanide-free gold leaching solutions, which represent emerging non-toxic gold technologies. In the current study, gold dissolution was investigated in ferric and Cupric Chloride solutions. The effect of the redox potential on the open circuit potential (OCP) and dissolution rate of gold was investigated experimentally in the parameter range of T = 25–95 °C, [Fe3+/Cu2+] = 0.02–1.0 M, [Cl−] = 1–5 M, pH = 0.0–2.0, and ωcyc = 2500 RPM. A high rotational speed was chosen to minimize the effects of limited mass transfer rate. The aim was to provide tools for estimating the gold dissolution rate in ferric and Cupric Chloride solutions, using the solution properties. The results showed that redox potentials, OCPs, and dissolution rates were constantly higher in ferric Chloride solutions compared to corresponding Cupric Chloride solutions. The multilinear regression models for redox potential showed that a rise in temperature and oxidant concentration increased the redox potential in both ferric and Cupric Chloride solutions. However, an increase in the Chloride concentration decreased the redox potential in ferric Chloride solutions, whereas the effect was the opposite in Cupric solutions. A rise in the pH value increased the redox potential in ferric solutions, but this was found to be an insignificant variable in Cupric Chloride leaching within the investigated parameter range. The redox potential had a positive correlation with OCP and the logarithm of the gold dissolution rate in both investigated systems. The results suggest that, in the Chloride leaching systems examined, the solution properties can be used to determine the redox potential, and furthermore, the redox potential can be used to estimate the gold dissolution rate. This study provides an experimentally verified tool for the robust estimation of the gold dissolution rate in Chloride systems.
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Features affecting the Cupric Chloride leaching of gold
Minerals Engineering, 2019Co-Authors: Sipi Seisko, Jari Aromaa, Mari LundstromAbstract:Abstract The current study investigated gold dissolution in Cupric Chloride solution, which is one of the most promising alternatives to replace cyanide, although not yet in operation on industrial scale. In this paper, the gold dissolution reaction rate and mechanism were studied by varying the process variables of temperature (28–95 °C), Cupric concentration (0.02–1.0 M), Chloride concentration (1–5 M), rotational speed (100–2500 RPM), and pH (0.5–2.0). The parameters affecting either the anodic or cathodic reaction, or both, were identified for the first time to the best of the authors’ knowledge in this wide range and with these parameter intervals. Tafel and linear polarization methods as well as cyclic voltammetry were used for pure gold with both rotating disk and stationary gold electrodes. An increase in the gold dissolution rate was observed with an increase in temperature, Chloride concentration, and rotational speed. Additionally, an increase in Cupric concentration ([Cu2+] = 0.02–0.75 M) promoted the gold dissolution rate, whereas the gold dissolution rate decreased with [Cu2+] from 0.75 to 1.0 M. The conditions for maximizing the gold dissolution rate in Cupric Chloride solution were concluded to be T > 55 °C, [Cu2+] = 0.5–0.75 M, [Cl−] = 5 M, and pH = 1.0 and the highest gold dissolution rate (2.9 · 10−4 mol m−2 s−1) was achieved at 95 °C with [Cu2+] = 0.5 M, [Cl−] = 5 M, pH = 1.0, and ωcyc = 2500 RPM. The pH was shown not to affect the gold dissolution rate at all, but only to affect the solubility of the oxidant. It was suggested that gold dissolved as aurous species in the conditions of this study, although the increase in Chloride concentration promoted the dissolution of gold as both, auric and aurous, species. The reaction mechanism was interpreted using mixed potential theory. An increase in temperature was shown to promote only the cathodic reduction of Cupric ion to cuprous at lower temperatures (28–55 °C); however, both the anodic gold dissolution reaction and cathodic Cupric reduction reaction were enhanced at higher temperatures (65–95 °C). The cathodic reaction was also enhanced with an increase in Cupric concentration (0.02–0.5 M), whereas the anodic reaction was promoted when the Cupric concentration was increased from 0.5 to 0.75 M. When the Cupric concentration was increased from 0.75 to 1.0 M, the cathodic reaction rate decreased. However, the reason for the decrease in the cathodic reaction rate was not clear. An increase in Chloride concentration enhanced the cathodic reaction in the investigated range (1–5 M), whereas an increase in rotational speed (i.e., improved mass transfer) increased the anodic gold dissolution rate, specifically at low rotational speeds.
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Open circuit potential and leaching rate of pyrite in Cupric Chloride solution
Canadian Metallurgical Quarterly, 2018Co-Authors: Heini Elomaa, Jari Aromaa, Lotta Rintala, Mari LundstromAbstract:ABSTRACTAs a refractory gold mineral, pyrite needs to be oxidised prior to gold leaching. In this study, the effect of [Cl−] concentration (40.6–149.8 g/L), [Cu2+] concentration (0.8–31.6 g/L), pH (1.5–2.5) and temperature (25–90 –C) on the pyrite leaching rate was investigated. In addition, the open circuit potential (OCP) values of pyrite in Cupric Chloride solution were investigated. A linear regression model was constructed to predict pyrite dissolution rate i.e. corrosion current density. It was shown that the temperature had a significant positive effect on pyrite dissolution, while increased Cupric ion concentration was also shown to provide some dissolution enhancement. According to the regression analysis, pH had no effect on the corrosion current density at OCP. Dissolution rates of pyrite varied between 0.05 and 2.9 µm/h. The activation energy values varied from 20 to 90 kJ/mol, indicated that the pyrite dissolution reaction rate was controlled by the chemical reaction or mixed mechanism rather...
Jari Aromaa - One of the best experts on this subject based on the ideXlab platform.
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process simulation based life cycle assessment of cyanide free refractory gold concentrate processing case study Cupric Chloride leaching
Minerals Engineering, 2020Co-Authors: Heini Elomaa, Jari Aromaa, Lotta Rintala, Mari LundstromAbstract:Abstract The development of cyanide-free gold leaching methods is becoming increasingly important due to the treatment of complex ores, where treatment by cyanidation is not economically viable. Cupric Chloride leaching provides an alternative leaching process to replace cyanidation. A detailed simulation of refractory gold concentrate processing by Cupric Chloride leaching is presented in this study. The simulation with mass and energy balances was built to be used as life cycle inventory data to evaluate the environmental impacts of the development stage Cupric Chloride process. Three cases, the Base Case (125 g/L Cl-), Mild Case (50 g/L Cl-), and Extremely Mild Case (20 g/L Cl-), were investigated in two flowsheet options. Loss of gold to wash waters was observed in the Flowsheet 1 cases, and therefore Flowsheet 2, with the recirculation of wash water to solvent extraction, was developed and investigated in order to achieve higher gold recovery. The gold extraction improved from around 85% to 99%. Chemical consumption (NaCl, NaBr, CuCl2) was greatly affected by the leaching conditions, higher concentrations consuming more initial chemicals. In milder conditions, efficient recycling of Chlorides could be obtained in the process, and no addition of NaCl was required. In the Extremely Mild Case, the Chloride concentration was close to sea water conditions (20 g/L), where sea water could be used to provide Chlorides for the process, and the effluent waters could be disposed of in the sea after purification. The global warming potential was estimated to be 12.5 t CO2-e/kg Au in Chloride leaching and was further decreased to 10.6 t CO2-e/kg Au in the mildest conditions (20 g/L Cl-). The milder Chloride leaching conditions (20 g/L Cl- and 50 g/L Cl-) were shown to decrease the acidification potential, eutrophication potential, and water depletion.
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Process simulation based life cycle assessment of cyanide-free refractory gold concentrate processing – Case study: Cupric Chloride leaching
Minerals Engineering, 2020Co-Authors: Heini Elomaa, Jari Aromaa, Lotta Rintala, Mari LundstromAbstract:Abstract The development of cyanide-free gold leaching methods is becoming increasingly important due to the treatment of complex ores, where treatment by cyanidation is not economically viable. Cupric Chloride leaching provides an alternative leaching process to replace cyanidation. A detailed simulation of refractory gold concentrate processing by Cupric Chloride leaching is presented in this study. The simulation with mass and energy balances was built to be used as life cycle inventory data to evaluate the environmental impacts of the development stage Cupric Chloride process. Three cases, the Base Case (125 g/L Cl-), Mild Case (50 g/L Cl-), and Extremely Mild Case (20 g/L Cl-), were investigated in two flowsheet options. Loss of gold to wash waters was observed in the Flowsheet 1 cases, and therefore Flowsheet 2, with the recirculation of wash water to solvent extraction, was developed and investigated in order to achieve higher gold recovery. The gold extraction improved from around 85% to 99%. Chemical consumption (NaCl, NaBr, CuCl2) was greatly affected by the leaching conditions, higher concentrations consuming more initial chemicals. In milder conditions, efficient recycling of Chlorides could be obtained in the process, and no addition of NaCl was required. In the Extremely Mild Case, the Chloride concentration was close to sea water conditions (20 g/L), where sea water could be used to provide Chlorides for the process, and the effluent waters could be disposed of in the sea after purification. The global warming potential was estimated to be 12.5 t CO2-e/kg Au in Chloride leaching and was further decreased to 10.6 t CO2-e/kg Au in the mildest conditions (20 g/L Cl-). The milder Chloride leaching conditions (20 g/L Cl- and 50 g/L Cl-) were shown to decrease the acidification potential, eutrophication potential, and water depletion.
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Effect of redox potential and OCP in ferric and Cupric Chloride leaching of gold
Hydrometallurgy, 2020Co-Authors: Sipi Seisko, Jari Aromaa, Mari LundstromAbstract:Abstract The research presented contributes to the global goal of responsible production by providing robust tools for the optimization of gold dissolution in cyanide-free gold leaching solutions, which represent emerging non-toxic gold technologies. In the current study, gold dissolution was investigated in ferric and Cupric Chloride solutions. The effect of the redox potential on the open circuit potential (OCP) and dissolution rate of gold was investigated experimentally in the parameter range of T = 25–95 °C, [Fe3+/Cu2+] = 0.02–1.0 M, [Cl−] = 1–5 M, pH = 0.0–2.0, and ωcyc = 2500 RPM. A high rotational speed was chosen to minimize the effects of limited mass transfer rate. The aim was to provide tools for estimating the gold dissolution rate in ferric and Cupric Chloride solutions, using the solution properties. The results showed that redox potentials, OCPs, and dissolution rates were constantly higher in ferric Chloride solutions compared to corresponding Cupric Chloride solutions. The multilinear regression models for redox potential showed that a rise in temperature and oxidant concentration increased the redox potential in both ferric and Cupric Chloride solutions. However, an increase in the Chloride concentration decreased the redox potential in ferric Chloride solutions, whereas the effect was the opposite in Cupric solutions. A rise in the pH value increased the redox potential in ferric solutions, but this was found to be an insignificant variable in Cupric Chloride leaching within the investigated parameter range. The redox potential had a positive correlation with OCP and the logarithm of the gold dissolution rate in both investigated systems. The results suggest that, in the Chloride leaching systems examined, the solution properties can be used to determine the redox potential, and furthermore, the redox potential can be used to estimate the gold dissolution rate. This study provides an experimentally verified tool for the robust estimation of the gold dissolution rate in Chloride systems.
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Features affecting the Cupric Chloride leaching of gold
Minerals Engineering, 2019Co-Authors: Sipi Seisko, Jari Aromaa, Mari LundstromAbstract:Abstract The current study investigated gold dissolution in Cupric Chloride solution, which is one of the most promising alternatives to replace cyanide, although not yet in operation on industrial scale. In this paper, the gold dissolution reaction rate and mechanism were studied by varying the process variables of temperature (28–95 °C), Cupric concentration (0.02–1.0 M), Chloride concentration (1–5 M), rotational speed (100–2500 RPM), and pH (0.5–2.0). The parameters affecting either the anodic or cathodic reaction, or both, were identified for the first time to the best of the authors’ knowledge in this wide range and with these parameter intervals. Tafel and linear polarization methods as well as cyclic voltammetry were used for pure gold with both rotating disk and stationary gold electrodes. An increase in the gold dissolution rate was observed with an increase in temperature, Chloride concentration, and rotational speed. Additionally, an increase in Cupric concentration ([Cu2+] = 0.02–0.75 M) promoted the gold dissolution rate, whereas the gold dissolution rate decreased with [Cu2+] from 0.75 to 1.0 M. The conditions for maximizing the gold dissolution rate in Cupric Chloride solution were concluded to be T > 55 °C, [Cu2+] = 0.5–0.75 M, [Cl−] = 5 M, and pH = 1.0 and the highest gold dissolution rate (2.9 · 10−4 mol m−2 s−1) was achieved at 95 °C with [Cu2+] = 0.5 M, [Cl−] = 5 M, pH = 1.0, and ωcyc = 2500 RPM. The pH was shown not to affect the gold dissolution rate at all, but only to affect the solubility of the oxidant. It was suggested that gold dissolved as aurous species in the conditions of this study, although the increase in Chloride concentration promoted the dissolution of gold as both, auric and aurous, species. The reaction mechanism was interpreted using mixed potential theory. An increase in temperature was shown to promote only the cathodic reduction of Cupric ion to cuprous at lower temperatures (28–55 °C); however, both the anodic gold dissolution reaction and cathodic Cupric reduction reaction were enhanced at higher temperatures (65–95 °C). The cathodic reaction was also enhanced with an increase in Cupric concentration (0.02–0.5 M), whereas the anodic reaction was promoted when the Cupric concentration was increased from 0.5 to 0.75 M. When the Cupric concentration was increased from 0.75 to 1.0 M, the cathodic reaction rate decreased. However, the reason for the decrease in the cathodic reaction rate was not clear. An increase in Chloride concentration enhanced the cathodic reaction in the investigated range (1–5 M), whereas an increase in rotational speed (i.e., improved mass transfer) increased the anodic gold dissolution rate, specifically at low rotational speeds.
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Open circuit potential and leaching rate of pyrite in Cupric Chloride solution
Canadian Metallurgical Quarterly, 2018Co-Authors: Heini Elomaa, Jari Aromaa, Lotta Rintala, Mari LundstromAbstract:ABSTRACTAs a refractory gold mineral, pyrite needs to be oxidised prior to gold leaching. In this study, the effect of [Cl−] concentration (40.6–149.8 g/L), [Cu2+] concentration (0.8–31.6 g/L), pH (1.5–2.5) and temperature (25–90 –C) on the pyrite leaching rate was investigated. In addition, the open circuit potential (OCP) values of pyrite in Cupric Chloride solution were investigated. A linear regression model was constructed to predict pyrite dissolution rate i.e. corrosion current density. It was shown that the temperature had a significant positive effect on pyrite dissolution, while increased Cupric ion concentration was also shown to provide some dissolution enhancement. According to the regression analysis, pH had no effect on the corrosion current density at OCP. Dissolution rates of pyrite varied between 0.05 and 2.9 µm/h. The activation energy values varied from 20 to 90 kJ/mol, indicated that the pyrite dissolution reaction rate was controlled by the chemical reaction or mixed mechanism rather...
Greg F. Naterer - One of the best experts on this subject based on the ideXlab platform.
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Particle formation and heat transfer in a gas-solid hydrolysis reactor with Cupric Chloride conversion to copper oxyChloride
International Journal of Heat and Mass Transfer, 2020Co-Authors: Aida Farsi, Ibrahim Dincer, Greg F. NatererAbstract:Abstract This paper presents a new predictive heat and mass transfer model of the gas-solid reaction in a Cupric Chloride decomposition and hydrolysis reactor during thermochemical water splitting in a copper-chlorine (Cu-Cl) cycle. The hydrated Cupric Chloride droplets descend in a narrow vessel through a reactor which forms a more coherent flow than a traditional hydrolysis spray reactor. The reactor operates based on falling solid particles and the gas-solid flow behavior in the reactor is analyzed to predict the total relative velocity of steam in its interaction with the CuCl2 (s). Aspen plus software and past literature are used for the thermodynamic and kinetic parameter evaluation. The present model reveals new physical insights into the gas/solid hydrodynamics in the hot zone of the hydrolysis reactor. From the analysis and results, the total relative velocity of steam through the height of the furnace varies from 0.32 m/s at the bottom to 0.12 m/s at the top. Furthermore, at the steam/CuCl2 molar ratio of 15 for an increase of Cupric Chloride volumetric flow rate from 8 ml/min into 25 ml/min, the average net heat transfer rate increases from 1.85 kW into 5.45 kW.
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Kinetic and hydrodynamic analyses of chemically reacting gas-particle flow in Cupric Chloride hydrolysis for the Cu-Cl cycle
International Journal of Hydrogen Energy, 2019Co-Authors: Aida Farsi, Ibrahim Dincer, Öznur Kayhan, Calin Zamfirescu, Greg F. NatererAbstract:Abstract The non-catalytic reaction of Cupric Chloride with steam to produce copper-oxy-Chloride solid and hydrogen Chloride gas is one of the most challenging steps in the copper-chlorine (Cu–Cl) thermochemical water splitting cycle of hydrogen production. Researchers at the University of Ontario Institute of Technology have designed a reactor in which a CuCl2 (aq) solution is atomized and reacted in a furnace where superheated steam is drawn in a counter-current stream. This study develops a new predictive model of the transport mechanisms of the hydrolysis reaction to predict the conversion of CuCl2(s) into the products. The hydrodynamic model estimates the residency time of the reactants in the reaction, and the kinetics predicts the gas-solid reaction through the shrinking core diffusion model (SCM). It is shown that the maximum conversion of CuCl2 is limited by the reactant velocity, reaction temperature, steam partial pressure and particle size. Results of the lab-scale experimental hydrolysis unit are presented and discussed.
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Effects of atomization conditions and flow rates on spray drying for Cupric Chloride particle formation
International Journal of Hydrogen Energy, 2011Co-Authors: V.n. Daggupati, Greg F. Naterer, Kamiel Gabriel, R. Gravelsins, Zhaolin WangAbstract:Abstract This paper examines the effects of different operating variables on Cupric Chloride (CuCl2) powder formation in a copper-chlorine (Cu–Cl) thermochemical cycle of hydrogen production. Experiments have been performed in two different spray drying units to identify the effects of the main operating variables on the Cupric Chloride powder quality. The experiments also examine the formation of powders using low temperature heat available from nuclear, solar and other industrial sources to remove moisture from solutions. The atomization liquid flow rate, atomization pressure and drying air inlet temperature are identified as independent variables. The moisture content, bulk density, particle size distribution and morphology are the dependent variables representing the powder quality. Experimental data have been analyzed for cohesive force and free flow characterization of powders using the Hausner ratio.
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Hydrodynamic gas–solid model of Cupric Chloride particles reacting with superheated steam for thermochemical hydrogen production
Chemical Engineering Science, 2008Co-Authors: Yousef Haseli, Ibrahim Dincer, Greg F. NatererAbstract:Abstract This paper examines the transport phenomena of a non-catalytic reaction of Cupric Chloride particles with superheated steam in a fluidized bed, as part of a copper–chlorine (Cu–Cl) thermochemical cycle for nuclear-based hydrogen production. As both Cupric Chloride and steam participate in the chemical reaction, it is necessary to develop a new model that predicts the conversion of Cupric Chloride particles, as well as steam. This incorporates features of a uniform reaction model (Volumetric Model; VM) and a Shrinking Core Model (SCM). Due to little or no experimental data available for the hydrodynamics and chemistry of the reaction, the above two models are considered as limiting cases. Separate numerical solution procedures are developed to monitor the effects of various parameters on the conversion of CuCl 2 particles and steam. Also, the new solution algorithms are used to predict outputs for a typical bench-scale reactor and operating conditions. From the numerical results, under the assumption of VM or SCM, the conversion of steam decreases with superficial velocity, whereas the conversion of solid particles increases. Also, a higher bed inventory leads to higher conversion of both reactants. SCM predicts higher values for the reactant conversions, compared to VM. The new solution procedures may be utilized for parametric studies that observe the effects of different process parameters on the fluidized bed performance.
G F Naterer - One of the best experts on this subject based on the ideXlab platform.
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fluid particle mass transport of Cupric Chloride hydrolysis in a fluidized bed
International Journal of Heat and Mass Transfer, 2009Co-Authors: Yousef Haseli, G F Naterer, Ibrahim DincerAbstract:This paper examines the mass transport phenomena of a hydrolysis reaction involving Cupric Chloride particles and superheated steam in a fluidized bed, as a part of the copper–chlorine thermochemical cycle for nuclear-based hydrogen production. The Gomez-Barea method was extended and utilized for the purpose of this study. A uniform reaction model (Volumetric Model; VM) and Shrinking Core Model (SCM) were used for limiting cases of the conversion processes. Using the solution procedures developed for each case, the effects of different parameters (such as the superficial gas velocity, bed inventory, and process temperature) were investigated in terms of the conversion of CuCl2 particles and steam.
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thermochemical hydrogen production with a copper chlorine cycle ii flashing and drying of aqueous Cupric Chloride
International Journal of Hydrogen Energy, 2008Co-Authors: G F Naterer, V.n. Daggupati, Kamiel Gabriel, G D Marin, Z WangAbstract:Abstract This paper examines the evaporative drying of aqueous Cupric Chloride (CuCl2) droplets in the copper–chlorine (Cu–Cl) thermochemical cycle of hydrogen production. An aqueous CuCl2 stream exiting from an electrochemical cell is preheated to 150 °C, before entering a flash evaporator to produce solid CuCl2(s). New innovations of heat recovery aim to develop alternatives that reduce costs and improve efficiency of the evaporation process for CuCl2 particle production. The liquid phase flashes due to a sudden pressure drop. Analytical solutions are developed for the Cupric Chloride spraying and drying processes, including empirical correlations for heat and mass transfer, based on a single droplet of aqueous CuCl2 solution. The study shows that considerable drying can be accomplished through differentials of humidity alone. It also shows that benefits of flashing the solution to enhance drying are relatively minor, compared to the rate of evaporative drying in the spray drying process.
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hydrodynamic gas solid model of Cupric Chloride particles reacting with superheated steam for thermochemical hydrogen production
Chemical Engineering Science, 2008Co-Authors: Yousef Haseli, Ibrahim Dincer, G F NatererAbstract:Abstract This paper examines the transport phenomena of a non-catalytic reaction of Cupric Chloride particles with superheated steam in a fluidized bed, as part of a copper–chlorine (Cu–Cl) thermochemical cycle for nuclear-based hydrogen production. As both Cupric Chloride and steam participate in the chemical reaction, it is necessary to develop a new model that predicts the conversion of Cupric Chloride particles, as well as steam. This incorporates features of a uniform reaction model (Volumetric Model; VM) and a Shrinking Core Model (SCM). Due to little or no experimental data available for the hydrodynamics and chemistry of the reaction, the above two models are considered as limiting cases. Separate numerical solution procedures are developed to monitor the effects of various parameters on the conversion of CuCl 2 particles and steam. Also, the new solution algorithms are used to predict outputs for a typical bench-scale reactor and operating conditions. From the numerical results, under the assumption of VM or SCM, the conversion of steam decreases with superficial velocity, whereas the conversion of solid particles increases. Also, a higher bed inventory leads to higher conversion of both reactants. SCM predicts higher values for the reactant conversions, compared to VM. The new solution procedures may be utilized for parametric studies that observe the effects of different process parameters on the fluidized bed performance.
Ibrahim Dincer - One of the best experts on this subject based on the ideXlab platform.
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Particle formation and heat transfer in a gas-solid hydrolysis reactor with Cupric Chloride conversion to copper oxyChloride
International Journal of Heat and Mass Transfer, 2020Co-Authors: Aida Farsi, Ibrahim Dincer, Greg F. NatererAbstract:Abstract This paper presents a new predictive heat and mass transfer model of the gas-solid reaction in a Cupric Chloride decomposition and hydrolysis reactor during thermochemical water splitting in a copper-chlorine (Cu-Cl) cycle. The hydrated Cupric Chloride droplets descend in a narrow vessel through a reactor which forms a more coherent flow than a traditional hydrolysis spray reactor. The reactor operates based on falling solid particles and the gas-solid flow behavior in the reactor is analyzed to predict the total relative velocity of steam in its interaction with the CuCl2 (s). Aspen plus software and past literature are used for the thermodynamic and kinetic parameter evaluation. The present model reveals new physical insights into the gas/solid hydrodynamics in the hot zone of the hydrolysis reactor. From the analysis and results, the total relative velocity of steam through the height of the furnace varies from 0.32 m/s at the bottom to 0.12 m/s at the top. Furthermore, at the steam/CuCl2 molar ratio of 15 for an increase of Cupric Chloride volumetric flow rate from 8 ml/min into 25 ml/min, the average net heat transfer rate increases from 1.85 kW into 5.45 kW.
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Kinetic and hydrodynamic analyses of chemically reacting gas-particle flow in Cupric Chloride hydrolysis for the Cu-Cl cycle
International Journal of Hydrogen Energy, 2019Co-Authors: Aida Farsi, Ibrahim Dincer, Öznur Kayhan, Calin Zamfirescu, Greg F. NatererAbstract:Abstract The non-catalytic reaction of Cupric Chloride with steam to produce copper-oxy-Chloride solid and hydrogen Chloride gas is one of the most challenging steps in the copper-chlorine (Cu–Cl) thermochemical water splitting cycle of hydrogen production. Researchers at the University of Ontario Institute of Technology have designed a reactor in which a CuCl2 (aq) solution is atomized and reacted in a furnace where superheated steam is drawn in a counter-current stream. This study develops a new predictive model of the transport mechanisms of the hydrolysis reaction to predict the conversion of CuCl2(s) into the products. The hydrodynamic model estimates the residency time of the reactants in the reaction, and the kinetics predicts the gas-solid reaction through the shrinking core diffusion model (SCM). It is shown that the maximum conversion of CuCl2 is limited by the reactant velocity, reaction temperature, steam partial pressure and particle size. Results of the lab-scale experimental hydrolysis unit are presented and discussed.
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fluid particle mass transport of Cupric Chloride hydrolysis in a fluidized bed
International Journal of Heat and Mass Transfer, 2009Co-Authors: Yousef Haseli, G F Naterer, Ibrahim DincerAbstract:This paper examines the mass transport phenomena of a hydrolysis reaction involving Cupric Chloride particles and superheated steam in a fluidized bed, as a part of the copper–chlorine thermochemical cycle for nuclear-based hydrogen production. The Gomez-Barea method was extended and utilized for the purpose of this study. A uniform reaction model (Volumetric Model; VM) and Shrinking Core Model (SCM) were used for limiting cases of the conversion processes. Using the solution procedures developed for each case, the effects of different parameters (such as the superficial gas velocity, bed inventory, and process temperature) were investigated in terms of the conversion of CuCl2 particles and steam.
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hydrodynamic gas solid model of Cupric Chloride particles reacting with superheated steam for thermochemical hydrogen production
Chemical Engineering Science, 2008Co-Authors: Yousef Haseli, Ibrahim Dincer, G F NatererAbstract:Abstract This paper examines the transport phenomena of a non-catalytic reaction of Cupric Chloride particles with superheated steam in a fluidized bed, as part of a copper–chlorine (Cu–Cl) thermochemical cycle for nuclear-based hydrogen production. As both Cupric Chloride and steam participate in the chemical reaction, it is necessary to develop a new model that predicts the conversion of Cupric Chloride particles, as well as steam. This incorporates features of a uniform reaction model (Volumetric Model; VM) and a Shrinking Core Model (SCM). Due to little or no experimental data available for the hydrodynamics and chemistry of the reaction, the above two models are considered as limiting cases. Separate numerical solution procedures are developed to monitor the effects of various parameters on the conversion of CuCl 2 particles and steam. Also, the new solution algorithms are used to predict outputs for a typical bench-scale reactor and operating conditions. From the numerical results, under the assumption of VM or SCM, the conversion of steam decreases with superficial velocity, whereas the conversion of solid particles increases. Also, a higher bed inventory leads to higher conversion of both reactants. SCM predicts higher values for the reactant conversions, compared to VM. The new solution procedures may be utilized for parametric studies that observe the effects of different process parameters on the fluidized bed performance.
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Hydrodynamic gas–solid model of Cupric Chloride particles reacting with superheated steam for thermochemical hydrogen production
Chemical Engineering Science, 2008Co-Authors: Yousef Haseli, Ibrahim Dincer, Greg F. NatererAbstract:Abstract This paper examines the transport phenomena of a non-catalytic reaction of Cupric Chloride particles with superheated steam in a fluidized bed, as part of a copper–chlorine (Cu–Cl) thermochemical cycle for nuclear-based hydrogen production. As both Cupric Chloride and steam participate in the chemical reaction, it is necessary to develop a new model that predicts the conversion of Cupric Chloride particles, as well as steam. This incorporates features of a uniform reaction model (Volumetric Model; VM) and a Shrinking Core Model (SCM). Due to little or no experimental data available for the hydrodynamics and chemistry of the reaction, the above two models are considered as limiting cases. Separate numerical solution procedures are developed to monitor the effects of various parameters on the conversion of CuCl 2 particles and steam. Also, the new solution algorithms are used to predict outputs for a typical bench-scale reactor and operating conditions. From the numerical results, under the assumption of VM or SCM, the conversion of steam decreases with superficial velocity, whereas the conversion of solid particles increases. Also, a higher bed inventory leads to higher conversion of both reactants. SCM predicts higher values for the reactant conversions, compared to VM. The new solution procedures may be utilized for parametric studies that observe the effects of different process parameters on the fluidized bed performance.
